Hydraulic pump.



J. DAVIDSON.

HYDRAULIC PUMP.

APPLICATION rILED JUNE za, 1912.

. Patented July 14, 1914.

JOSEPH DAVIDSON, OF EAST PQINT, GEORGA, ASSIGNOR 0F ONEJEIALF T0 @MEAN MACHINE & MANUFACTUWl-ING COMANY, A CORPORATION F NORTH CBOLINA.

Ernestine rotar,

Specification of Letters Patent.

Patented duly 1d, 1914.

To all whom it may concern Be it known that l, Josera Devmsoiv, citizen of the United States, und resident of Eestloint, county of Fulton, and State of Georgie, have invented an Improvement Hydraulic Pumps, of which the following 1s a speciiication.

My invention has reference to hydraulic pumps and consists o certain improvements which are fully set forth in the following speciication und shown in the ecconipeny-` f drawings which form e part thereot` -mlfhe object of my invention is to provide a constructiouof pump which shell embody Simplicity .sud reliability; and which `will operete, within itself, to produce e gradually increasing pressure and meintein seidpres sure et any predetermined amount, without the use of automatic devicesor governing ythe speed of the pump or controlling the pressure as heretofore hss been customary.

' My object is also, to provide s pump which will operate economically end require the expenditure of no power beyond that actually required to raise the pressure to und maintain it et the pressure oint required.

` My invention consists of t e im rovements which ere fully described hereine er and deined in the claims; and my invention will be better understood by reference to the drawings, in which:

Figure 1 is e plan .view of e pump embodying my improvements; und Fig. 2 is e sectional elevation 'of the same teken on line :vp-m. v

2 is the bed plate and supports the cy1- inders Il by the brackets 3, 3, and the trans verse frames 5, 5, in which the cylinders i are Supported. In the particular illustrar tion, l have shown two cylinders fl, el, euch havin@ oppositely directed plunger chambers 6, 6, so that, by Way oi esemple l provide four single acting pumps which may be opn erated separately, in pairs or in multiple as desired, by simply coupling up the induction and eductiou pipes in e lsuitable manner to secure the particular results desired` The plungers 13 work-in the right handplunger chambers 6 und are extended through the i cross head 14. These giungere have independent collars 19 `resting against the Shouldered portions 21 on the plungers, und 'between these collars und the cross heed, are arranged coiled springs 20. The ends of the plungers extend into the space 23 in the cross head and hevelock-nuts 22 which cause the plungers to be withdrawn positively by the cross heed and muy also ect to adjust the tension of the s rings 20. The cross head 14 is guided on t e guide rods 25 extending from the transverse frames 5 to the bearings 1B for the power shaft 17. This power shaft 17 is providedv with s pulley 2e to rotate it and is further furnished -with the eccentrics 16 which operate eccentric rods 15, whose ends are hinged to the cross head 14. B ro toting the shaft 17, the cross, heed' si. the plungers 13 are reciprocated and .the pump ing. or compressing of the plnngersls epphed through the springs 20,v whose power determines the pressure to be produced by the plungers. By adjusting the nuts 22 of the respective plungers, the tensions of the springs muy be adjusted to yield to any pressure resistance desired which may be exerted upon the plungers. The cylinders have each s plun er chamber provided with inlet .and outlet c eck valves. These valves are Jformed in plugs which are screwed into threaded apertures in the cylinder body.

'l' are the outlet check plugs and huveball valves 8 seating uporr valve seats in ,the plugs; und 10 are the inlet check plugs und are provided with the ball valves 9. scetm upon vulve seats in the plugs. The fluid muy be supplied to theiulet plugs and conducted away from the outlet plugs by suite-ble pipes. By the use of the plug check valves, the con-- struction is slm e und reliable, takes up small space and for cleening or repair. Instead of using bell check` valves, the valve pieces muy be made in eny other` suitable manner.

The cylinders may be provided with suitn able smiling-boxes and packing as indicated et l2, through which the plungers 13' und 14.- reciprocate. The second vset of plungers 14- ure, `in all materiel respects, the same us the other plungers being provided with the shoulder 28 against which thel collars 50 e plugs are easily removed and Whiie the cro-ss head rest; and having their ends loosely extendm ing through the cross head Q6 and provided with lock-nuts 29. .Between the cross head 26 and the respective collars 30 are coiled springs Q7 ivliich surround the plungers. The cross head is secured te the rods 3l which are guided through the transverse frames and secured to the cross head 14, as shown.' It will be understood that when the cross heed 141 is reciprocated, the cross head is also reciprocated and as tiiese are upon opposite ends of the cylinders li, 'the plungers operated by the respective cross heads will lie moved simultaneously. ln this way, the fluid Will be compressed in one set ofplunger chambers and forced from the cylinder by the plungers '13, `.vhile it is being sucked into the other set of plunger cham bers by the plungeifs lli, and vice versa.

The action of the pump is as follows: 1When the pump is Working under low or moderate pressure which does not give sufficient pressure against the ends oi the plungers to cause the springs to compress, the plungers ineke full strokes, receiving and 'discharging the full capacity of the cylinders. As the pressure rises, it eventually' becomes suilicient to compress the springs; has a fixed travel, the travel of the plungers is gradually reduced, thus reducing the volume oi' the liquid being received and discharged, until the final predetermined pressure is reached, which is sufficient to compress the springs to the amount equal to the 'full travel of the cross head. `When the travel of the plungers ceases and the pressure is held at the meximuin point es long as desired, no more liquid will he received or delivered by the pump until. the pressure is reduced. Where o, number of different hydraulic presses or other machines are operated from one pump, it is intended to have a suiiic: gi in cach pump in order that the discharge from one plunger een be connected separately to each press, each press having separate pressure sugplv and is not effected by the operation of any' other press in the battery. The nuts on the end of the pluncan be adjusted so as to tighten or loosen theip'rings, thus causing them to force the plin'ige against a greater or lesser pressure, as desired- The power required to compress the springs is couuteractedby the power the springs give back on the return stroke, hence no power is being; Wasted.

lt .will be understood that in the pump structure shown, the plungers :md their chambers may he empli'iyed to supply Huid pressure to separate pieces of machinery, or they may be operate-:i in .pfurs or in multiple, as the necessities may dictate; and While i have shown the use of tour plungers and chambers, a number or a greater number nie-y be provided and be ogerated from lent number of pion` moar-see the seme shaft 17, and l do not restrict myi soli.' in this respect.

l have illustrated e. construction of my invention, by Way of example, 'which is that which l prefer in commercial practice, but i do not confine myself to the details shown, as these may be modified without departing from the spirit oi' the invention. u

Having now described my invention, what I claim new' and desire to secure by Letters Patent, is: v

l. ln a hydraulic pump, the combination of a hase, a pair of frames supported by said base and. suitably spaced apart, a cylinder fixed Abetween said iframes having a valved inlet and a valved outlet, a plunger mounted for sliding movement in said cylinder, a cross head connected to said plunger to positively actuate said plunger in one direction oi' moi/'ement and yieldin'gly connected. to said plunger to zictuate said plunger in the opposite direction, stationary guide rods fixed to said frames upon which said cross head is adapted to reciprocate to guide it in rotation to the cylinder, and means to reciprocate said cross head having a connection therewith and supported by the stationary rods.

2. in a hydraulic pump, the combination of a base, a pair of frames supported by said base and suitably spaced apart, a' cylin der xed between said frames having a plurality of valved inicts and a plurality' of valved outlets, a pair of plungers mounted for sliding movement in seid cylinder and extending in opposite directions, cross heads respectively connected to said plungers to positively actuate said plungers in their suction movements and yieldingly connected to said plungers in the opposite direction, springs between the cross heads and the plungers to cause them to yieldingly move on the compression strokes, rods secured to and connecting said cross heads and slidingly mounted iu seid frames whereby the cross lie-:ids are simultaneously moved in the same directions, guide rods fixed to said iframes upon which one of said cross heads is adaptedr to reciprocate end be guided, and Ineens to reciprocate said cross head 3. In a hydraulic pump, the/combination ott' a cylinder having plunger chambers eXn tending` and opening` in'opposite directions, plunger-s lfor saidI chambers respectively eX- tendinsf beyond the cylinder at cach end thcreoi, stuilizigdioxes around the plungers, a reciprocating` frame through each end of which the free ends of the plungers extend with a sliding lit, springs arranged between the frame and each o the plungers for sub jecting said plungers toeeiastic pressure in' a direction to move them into the respective chambers, loci; nuts screwed upon the ends of the piangere to provide adjustable adjustmciits wl'iereby the plungcrs may he adjusted in. the frame land the cylinders and the frames operate the plunger-S in' withdrawing them outwardly in respect to the chambers and also for adjusting the tensions 'i of the Springs to vary the maximum com pression, and power devices o reciprocatmg the frame.

In testimony of which invention, hesunto set my hemd; 

